Dynamic prediction of pregnancy outcome after previous stillbirth or perinatal death: pilot study to establish proof-of-concept and explore method feasibility.

Objective: To establish proof-of-concept for the dynamic prediction of adverse pregnancy outcome in women with a history of stillbirth or perinatal death, repeatedly throughout the pregnancy.

Methods: A retrospective cohort study of women in a subsequent pregnancy following previous perinatal loss, who received antenatal care at a tertiary hospital between January 2014 and December 2017, was used as the basis for exploratory prognostic model development. Models were developed to repeatedly predict a composite adverse outcome (stillbirth or neonatal death, 5-min Apgar score < 7, umbilical artery pH ≤ 7.05, admission to the neonatal intensive care unit for longer than 24 h, preterm birth (< 37 completed weeks) or birth weight < 10^th centile) using the findings of sequential ultrasound scans for fetal biometry and umbilical and uterine artery Doppler.

Results: In total, 506 participants were eligible, of whom 504 were included in the analysis. An adverse pregnancy outcome was experienced by 110 (22%) participants. The ability to predict the composite outcome using repeated head circumference and estimated fetal weight measurements improved as the pregnancy progressed (e.g. area under the receiver-operating-characteristics curve improved from 0.59 at 24 weeks' gestation to 0.74 at 36 weeks' gestation), supporting proof-of-concept. Predictors to include in dynamic prediction models were identified, including ultrasound measurements of fetal biometry, umbilical and uterine artery Doppler and placental size and shape.

Conclusion: The present study supports proof-of-concept for dynamic prediction of adverse outcome in pregnancy following prior stillbirth or perinatal death, which could be used to identify risks earlier in pregnancy, while highlighting methodological challenges and requirements for subsequent large-scale model development studies. © 2024 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.